1 14-oz can, a mason jar, and some boiled water is all you need for this!
I was searching for a BPA-free alternative to boiling in the can, as the toxins leaching from the coating of the can into the product bothered me too much to try. I also have no patience for double-boiling when making banoffee pie, so this was the quickest way to achieve the gooey sweet dulce de leche filling.
Empty the can into a pint size-mason jar, seal the lid tightly. Place into a large saucepan and fill with water just-below the lid. Boil for 1 hour, or until thickened inside and a nice darkened caramel color.